802.1X is an IEEE standard for EAP encapsulation over wired or wireless Ethernet.

802.1X is also known as EAPoL (EAP over LAN). This only makes sense when you recall that EAP was originally designed for use over PPP.

802.1X Roles

802.1X defines three roles:

Name Description
Supplicant User or client requesting authentication
Authentication Server The server providing authentication
Authenticator The device which the Supplicant requests access to, and which requests access from the Authentication Server.

802.1X and RSN

802.1X is particularly well suited for wireless LAN applications because it requires very little processing power on the part of the Authenticator. In wireless LAN applications, the Authenticator is the Wireless Access Point (WAP).

The 802.11i RSN (Robust Security Network) protocol uses 802.1X to authenticate wireless devices to the network and to provide the dynamic keys it requires.